Liveright Publishing, the W.W. Norton imprint, will publish the prison letters of former South African president and anti-apartheid revolutionary Nelson Mandela. The book will include a foreword by Zamaswazi Dlamini-Mandela, Mandela's granddaughter.

The letters will be published in two editions: first, in a single volume containing roughly 250 selected letters timed for the centenary of Mandela's birth, in July 2018; and later in a two-volume collection. Many of the letters, written while Mandela was incarcerated in South Africa in four prisons between 1962 and 1990, have never been seen by the public.

Liveright acquired world rights from Blackwell & Ruth, which has long worked with the Nelson Mandela Foundation and the executors of Mandela's estate. Liveright's editor-in-chief, Robert Weil, who made the acquisition, has also previously worked with the foundation, on Nelson Mandela's Favorite African Folktales, which won the NAACP award in 2003. Sahm Venter, a former reporter for the Associated Press, will edit the volume.

"This collection of letters reminds us of the exceptional pressures on Nelson Mandela to succumb to a system which aimed to wipe him from the public consciousness and which expected him to die a prisoner," Venter said in a statement. "His resilience and his determination, in the face of enormous odds, to maintain his dignity and authority throughout are apparent in this rich first-hand account of his life in prison."